I live in Connecticut. It was recently in the single digits outside and I noticed on the ceilings near the outside walls in all rooms near the soffit side "wet water marks" and some drops of water. Also the attic hatch door had droplets of water all over the room side of it, they actually dropped on me thats how I noticed the problem. The inside temp at the time was about 53 degrees. I shut the heat at night then fire it up in the morning (oil prices). New roof, no leaks when it rains, new insulation in the attic vapor barrier side down towards the rooms. No pipes leaking. Thanks all!
The darker area on the attic hatch door is where the water was...